Prefix plugin clones with the username so shared clones don't collide

Clones of omarchy.clock become dhh.clock instead of local.clock, so a
published clone carries its author's namespace. The clone command owns
the id derivation and gains --edit to open the result in $EDITOR, and
the shell exposes clonedFrom in listPlugins so the plugin menu no longer
reconstructs clone ids.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

shell/shell.qml

@@ -938,6 +938,8 @@ ShellRoot {
         var isBarOption = Array.isArray(kinds) && kinds.indexOf("bar") !== -1
         var isBarWidget = Array.isArray(kinds) && kinds.indexOf("bar-widget") !== -1
         var active = isBarOption && shell.isActiveBarOption(id)
+        var metadata = plugins[id].omarchy
+        var clonedFrom = Util.isPlainObject(metadata) ? String(metadata.clonedFrom || "") : ""
         out.push({
           id: id,
           name: plugins[id].name,
@@ -952,7 +954,8 @@ ShellRoot {
           // that a caller offering the verbs does not have to read kinds and
           // work it out again.
           canDisable: !isBarOption,
-          firstParty: !!plugins[id].__isFirstParty
+          firstParty: !!plugins[id].__isFirstParty,
+          clonedFrom: clonedFrom
         })
       }
       // Consumers should not each invent their own presentation order.